Turbo Specs? What Psi Can I Run?

I traded a guy on H-T, my nitrous tank for a small turbo. The turbo is an IHI serial# RHB5 12288. what is the max psi for this turbo? (the guy i taded with said that it could handle up to 20PSI) and how would i rais the max psi? bigger compressor housing and wastgate?

psi is a pressure as measured at the map sensor. A turbo itself will be effective at different levels on different motors.
however, it will only flow XXX CFM's.

that said, i doubt it will see 20 psi.

waste gates control boost level, they don't make it or defeat it. that's what a boost controller is for.

that turbo is worthless (in my opinion of course) to even consider swapping compressor housings. It's small as hell, and won't offer you that much gain...
I'd say its good for a home made/junkyard set up on a d-series, and thats about it. Again, my opinion.